Preparation and dyeing of leather



Patented May 10, i927.

[UNITED STATES PATENT oFFicE;

creams-ensures LAMB, or BnnMonnsnY, LONDON, nuenmn.

PREPARATION AN!) DYEING F LEATHER.

No Drawing. Application filed June 9, 1925,3eria1 No. 36,052, and inGreat Britain April 27, 1925.

This invention relates to the dyeing of leather and provides a treatmentwhicheffects the equaldistribution andsolubilization of the natural.grease inthe skins and enables them to be dyed a level shade of colorand also gives greater penetration of the dyestuti' and enhancemen ot'the color produced.

According to this invention I treat the.

leather with a solution or emulsion of a .compound containing anaphthalene nucleus. The term is used in the generally accepted sense asrepresenting a nucleus of the form containing from 8-to 16 hydrogenatoms. The leatheremployed may be tanned either by vegetable or mineraltanning agents or dressed by the oil or aldehyde process. it has beenfound that the. treatmentby the compound containing'the naphthalenenucleus applied either before or during the process of dyein etfectssolubilizationof the natural andarti cial grease contained in theleather and'the leather is so modified that the dyestufi, penetratesmore deeply than is usually the case and there i.; considerable increasein the intensity of shade produced. Various compounds of the typereferred to can be uscdbut the compound preferred is hydrogenatednaphthalene, used either alone 3 in a soluble or finely divisible formor in an emulsified form obtained by the employment of emulsifyingagents, e. g, sodium, potassium or ammonium ricinoleate, hydrogenatedphenol soaps-,hydrogenated cresol soaps, sul-' phonated or soluble oilsof vegetable, animal or mineral origin, the salts of sulphonatedaromatic acids, or aromatic acids either used alone or in conjunctionwith each other; or'

the employment of a mixture of an emulsion conjunction with halogen orother hydrocarbon compounds;

The method of treatment may be considerably varied and the following arefour exa or solutionof hydrogenated naphthalene in East India tannedsheepskins and hides,

bark and sumach tanned calfskins, skivers,

genated naphthalene is added, and the goodstreated in the mixture for aperiod of about 15 minutes, when the requisite coal-tar dyestuti is thenadded and the treatment continued for a further period of minutes.

Ewample 2.

Vegetable tanned leathers, such' as enu merated above, are firstthoroughl wetted out, when an addition is made to t 1e vessel of- 2 percent to 3 per cent of a 90 per cent emulsion of hydrogenatednaphthalene, and the goods processed for any desirable period. They arethen washed and dyed with coaltar or natural dyestutl's by any of thecommon methods in use.

Example 3.

Ewample 4.

Ve etable, mineral tanned, or oil dressed or al ehyde leather is firstwetted in water by any of the ordinary methods and is then treated with2 per cent to 3\per cent'of an emulsion of per cent h drogenatednaphthalene, 10 per cent hytl soap, and 10 per cent ordinary ammonia orpotash soap, for a period of 30-minutes, when the dyein either by the adition of the requisite coal- ,t. l p e of the treatment, /p py h h, taror natural dyestufi' o the so ution, or by se arate treatment by anyordinary method.

t is to be understood thatthe term emulsion as used in the claims isintended to cover rogenated phenol process 1s proceeded with,

"W at I claim and desire to secure by Letters Patent of the UnitedStates is 1. lln the dyeing of leather, treating the leather with anemulsion of hydrogenated 5 naphthalene and with a dyeing agent.

2. ln the dyeing of leather, a process which consists in adding anemulsion of hydrogenated naphthalene to thedye bath.

3. lln the dyeing of leather, a process 10 which consists in employingan emulsion or a compound containing a naphthalene nuwearer) cleusinconjunction with coal-tar colouring matter and With a halogenhydrocarbon.

4 In the dyeing of leather, treating the leather With an emulsion of acompound containing 4 a naphthalene nucleus together with a solublericinoleate.

5. A process as in claim 4:, in which trichlorethylene is also employedwith the aforesaid substances.

MORRIS CHARLES LAMB.

